1. Field of the Invention
This invention relates to a new and improved horizontal magnet structure for electron beam heated evaporation source. More particularly, it relates to an electron beam heated source for use in a high vacuum environment to make high grade thin film coatings and the like. An electron-beam gun is positioned on one side of a turret containing multiple crucibles or an array of crucibles. The substance or substances which are to be evaporated are positioned in the individual crucibles. An electron beam gun is positioned such that the evaporated substance does not damage the gun. In order to direct the path of the electrons emitted from the gun to a particular crucible, a plurality of magnets is disposed horizontally on opposite sides of a particular crucible the substance of which is being evaporated, thereby creating a transverse magnetic field extending over the top of the gun and the substance to be evaporated. Positioning the magnets guides and focuses the electrons in a convex path upward and down into the substance in the crucible. The magnets may be either permanent or electro or a combination thereof.
2. Description of Related Art
The aforesaid patent application of which this is a continuation-in-part and the references cited by the Patent Office thereagainst adequately describes prior art known to Applicant. Magnetic measurements of intensity at various positions in the crucible area as well as above and well below the crucible top show that the main source of magnetic flux along vertically placed magnets is at the top ends and the area very close to the ends. It therefore is desirable that the geometry of the emitter, magnet and multiple crucibles be constructed in accordance with the present invention whereby the magnets are horizontally disposed. Where there is a turret-like array, it would be difficult to place vertical magnets around crucibles without great magnetic complexity ensuing. By using horizontally disposed magnets, the foregoing disadvantages are overcome.